12 Creating and Removing Application Containers and Seeds
You can create application containers and application seeds in several different ways. You can also remove application containers from a CDB, and you can remove application seeds from application containers.
Creating and Removing Application Containers
You can create application containers in several different ways, including using the PDB seed, cloning an existing PDB or non-CDB, and plugging in an unplugged PDB. You can also remove application containers from a CDB.
Creating Application Containers
You can use the CREATE PLUGGABLE DATABASE
statement to create an application container in a CDB.
About Creating an Application Container
The CREATE PLUGGABLE DATABASE ... AS APPLICATION CONTAINER
statement creates a new application container.
An application container consists of an application root and a collection of application PDBs that store data for one or more applications. The application PDBs are plugged into the application root, and you can optionally create an application seed for quick and easy creation of new application PDBs. The application PDBs and application root can share application common objects.
There are three types of application common objects:
-
Metadata-linked application common objects store the metadata for specific objects, such as tables, so that the containers that share the application common object have the same structure but different data.
-
Data-linked application common objects are defined once in the application root and shared as read-only objects in the context of hosted application PDBs.
-
Extended data-linked application common objects store shared data in the application root but also allow application PDBs to store data appended to that object. The appended data is local data that is unique to each application PDB.
You create an application container by including the AS APPLICATION CONTAINER
clause in the CREATE PLUGGABLE DATABASE
statement. You can use the following techniques to create an application container:
-
Using the PDB seed
-
Cloning an existing PDB or non-CDB
-
Relocating a PDB
-
Plugging in an unplugged PDB
To create an application container, the current container must be the CDB root and you must specify the AS APPLICATION CONTAINER
clause in the CREATE PLUGGABLE DATABASE
statement. You must create the application container using Oracle Managed Files.
Note:
An application container cannot be unplugged or dropped if any application PDBs belong to it.
Migrating Existing Applications to an Application Container
You can migrate an application to an application root by creating an application root using an existing PDB. You must complete additional tasks when you are migrating an existing application to an application container. The PDBs that you plug in must contain the application objects, including their data, and you must run procedures in the DBMS_PDB
package to specify which objects are shared. Also, when application common users, roles, or profiles exist in the application root, you must run procedures in the DBMS_PDB
package to specify that they are common.
After the application is migrated to the application root, you can create application PDBs in the application root, and create application PDBs using existing PDBs.
Preparing for Application Containers
Prerequisites must be met before creating an application container.
-
The CDB must exist.
-
The CDB must be in read/write mode.
-
The current user must be a common user whose current container is the CDB root.
-
The current user must have the
CREATE PLUGGABLE DATABASE
system privilege. -
You must decide on a unique application container name for every application container. Every application container name must be unique with respect to all containers in a single CDB, and every application container name must be unique within the scope of all the CDBs whose database instances are reached through a specific listener.
The application container name is used to distinguish an application container from other containers in the CDB. Application container names follow the same rules as service names, which includes being case-insensitive.
-
You must create the containing using Oracle Managed Files.
-
If you are creating an application container in an Oracle Data Guard configuration with a physical standby database, then additional tasks must be completed before creating an application container.
-
If you are migrating an existing application to an application container using installation scripts, then the scripts must be available to run.
-
If you are migrating an existing application to an application container using a PDB, then it must be possible to clone the PDB to the application root or plug in the PDB into the application root.
Creating an Application Container
You can create an application container using the CREATE PLUGGABLE DATABASE
statement with the AS APPLICATION CONTAINER
clause.
Example 12-1 Creating an Application Container Using the PDB seed
This example assumes the following factors:
-
Storage limits are not required for the application container. Therefore, the
STORAGE
clause is not required. -
The application container does not require a default tablespace.
-
The
PATH_PREFIX
clause is not required. -
The
FILE_NAME_CONVERT
clause and theCREATE_FILE_DEST
clause are not required.Either Oracle Managed Files is enabled for the CDB, or the
PDB_FILE_NAME_CONVERT
initialization parameter is set. The files associated with the PDB seed will be copied to a new location based on the Oracle Managed Files configuration or the initialization parameter setting. -
There is no file with the same name as the new temp file that will be created in the target location. Therefore, the
TEMPFILE REUSE
clause is not required. -
No predefined Oracle roles need to be granted to the
PDB_DBA
role.
The following statement creates the application container from the PDB seed:
CREATE PLUGGABLE DATABASE salesact AS APPLICATION CONTAINER
ADMIN USER salesadm IDENTIFIED BY password;
Example 12-2 Creating an Application Container by Cloning a Local PDB
This example assumes the following factors:
-
The
PATH_PREFIX
clause is not required. -
The
FILE_NAME_CONVERT
clause is required to specify the target locations of the copied files. In this example, the files are copied from/disk1/oracle/pdb1/ to /disk2/oracle/hract/
.The
CREATE_FILE_DEST
clause is not used, and neither Oracle Managed Files nor thePDB_FILE_NAME_CONVERT
initialization parameter is used to specify the target locations of the copied files.To view the location of the data files for a PDB, run the query in "Example 19-7".
-
Storage limits must be enforced for the application root. Therefore, the
STORAGE
clause is required. Specifically, all tablespaces that belong to the application root must not exceed 2 gigabytes. This storage limit does not apply to the application PDBs that are plugged into the application root. -
There is no file with the same name as the new temp file that will be created in the target location. Therefore, the
TEMPFILE REUSE
clause is not required.
Given the preceding factors, the following statement clones hract
as an application container from pdb1
:
CREATE PLUGGABLE DATABASE hract AS APPLICATION CONTAINER FROM pdb1
FILE_NAME_CONVERT = ('/disk1/oracle/pdb1/', '/disk2/oracle/hract/')
STORAGE (MAXSIZE 2G);
Note:
If you are migrating an existing application to the new application container, then follow the instructions in "Migrating an Existing Application to an Application Container".
Example 12-3 Creating an Application Container by Plugging In an Unplugged PDB
This example assumes the following factors:
-
The new application container is not based on the same unplugged PDB that was used to create an existing PDB or application container in the CDB. Therefore, the
AS
CLONE
clause is not required. -
The
PATH_PREFIX
clause is not required. -
The XML file does not accurately describe the current locations of the files. Therefore, the
SOURCE_FILE_NAME_CONVERT
clause orSOURCE_FILE_DIRECTORY
clause is required. In this example, the XML file indicates that the files are in /disk1/oracle/payroll/, but the files are in /disk2/oracle/payroll/, and theSOURCE_FILE_NAME_CONVERT
clause is used. -
The files are in the correct location. Therefore,
NOCOPY
is included. -
Storage limits must be enforced for the application container. Therefore, the
STORAGE
clause is required. Specifically, all tablespaces that belong to the application container must not exceed 2 gigabytes. -
A file with the same name as the temp file specified in the XML file exists in the target location. Therefore, the
TEMPFILE REUSE
clause is required.
The following statement plugs in the PDB:
CREATE PLUGGABLE DATABASE payrollact AS APPLICATION CONTAINER
USING '/disk1/usr/payrollpdb.xml'
SOURCE_FILE_NAME_CONVERT = ('/disk1/oracle/payroll/',
'/disk2/oracle/payroll/')
NOCOPY
STORAGE (MAXSIZE 2G)
TEMPFILE REUSE;
Note:
If you are migrating an existing application to the new application container, then follow the instructions in "Migrating an Existing Application to an Application Container".
Unplugging an Application Container from a CDB
You can unplug an application container from a CDB.
About Unplugging an Application Container
Unplugging an application container disassociates the application container from a CDB.
Typically, you unplug an application container when you want to move the application container to a different CDB. Also, you can unplug the application container when you no longer want it to be available.
Unplugging an application container is similar to unplugging a PDB. To unplug an application container, connect to its CDB root and use the ALTER PLUGGABLE DATABASE
statement to specify an XML file or a .pdb
file. When you specify an XML file (.xml
extension), it will contain metadata about the application container after it is unplugged. The SQL statement creates the XML file, and it contains the required information to enable a CREATE PLUGGABLE DATABASE
statement on a target CDB to plug in the application container. When you specify a .pdb
file, it contains a compressed archive of the XML file that describes the application container and the files used by the application container (such as the data files and wallet file). A .pdb
file enables you to copy a single, compressed file (instead of multiple files) to a new location to plug the application container into a CDB.
Before it can be unplugged, the application container must not have any application PDBs plugged into it, and it must be closed. When you unplug an application container, the unplugged application container is in mounted mode. The unplug operation makes some changes in the application container’s data files to record, for example, that the application container was successfully unplugged. Because it is still part of the CDB, the unplugged application container is included in an RMAN backup of the entire CDB. Such a backup provides a convenient way to archive the unplugged application container in case it is needed in the future.
To completely remove the application container from the CDB, you can drop it. The only operation supported on an unplugged application container is dropping the application container. The application container must be dropped from the CDB before it can be plugged back into the same CDB. An application container is usable only when it is plugged into a CDB.
See Also:
-
"Modifying the Open Mode of PDBs" for information about closing a PDB
-
"Modifying a PDB at the System Level" for information about initialization parameters and unplugged PDBs
-
Oracle Database Security Guide for information about common users and local users
Unplugging an Application Container
Unplug an application container by using an ALTER PLUGGABLE DATABASE ... UNPLUG INTO
statement.
Prerequisites
You must meet the following prerequisites:
-
The current user must have
SYSDBA
orSYSOPER
administrative privilege, and the privilege must be either commonly granted or locally granted in the PDB. The user must exercise the privilege usingAS
SYSDBA
orAS
SYSOPER
at connect time. -
The application container must have been opened at least once.
-
The application container must not have any application PDBs plugged into it.
-
The application container must not have an application seed plugged into it.
Note:
If you are unplugging an application container that includes data that was encrypted with Transparent Data Encryption, then follow the instructions in Oracle Database Advanced Security Guide.
To unplug an application container:
-
In SQL*Plus, ensure that the current container is the root of the CDB.
-
Close the application container.
In an Oracle Real Application Clusters (Oracle RAC) environment, the application container must be closed on all instances.
-
Run the
ALTER PLUGGABLE DATABASE
statement with theUNPLUG INTO
clause, and specify the application container to unplug and the name and location of the application container’s XML metadata file or .pdb file.
Example 12-4 Unplugging Application Container salesact
This ALTER PLUGGABLE DATABASE
statement unplugs the application container salesact
and creates the salesact.xml
metadata file in the /oracle/data/ directory
:
ALTER PLUGGABLE DATABASE salesact UNPLUG INTO '/oracle/data/saleact.xml';
Dropping an Application Container
You can drop an application container when you want to move the application container from one CDB to another or when you no longer need the application container.
Dropping an application container is very similar to dropping a PDB. When you drop an application container, the control file of the CDB is modified to eliminate all references to the dropped application container. Archived redo log files and backups associated with the application container are not removed, but you can use Oracle Recovery Manager (RMAN) to remove them.
When dropping an application container, you can either keep or delete the application container’s data files by using one of the following clauses in the DROP PLUGGABLE DATABASE
statement:
-
KEEP DATAFILES
, the default, retains the data files.The application container’s temp file is removed even when
KEEP DATAFILES
is specified because the temp file is no longer needed. -
INCLUDING DATAFILES
removes the data files from disk.If an application container was created with the
SNAPSHOT COPY
clause, then you must specifyINCLUDING DATAFILES
when you drop the application container.
The following prerequisites must be met:
-
The application container must be in mounted mode, or it must be unplugged.
-
The current user must have
SYSDBA
orSYSOPER
administrative privilege, and the privilege must be either commonly granted or locally granted in the application container. The user must exercise the privilege usingAS SYSDBA
orAS SYSOPER
at connect time. -
The application container must not have any application PDBs plugged into it.
-
The application container must not have an application seed plugged into it.
Note:
This operation is destructive.
To drop an application container:
-
In SQL*Plus, ensure that the current container is the CDB root.
See "About the Current Container" and "Accessing a Container in a CDB with SQL*Plus".
-
Run the
DROP
PLUGGABLE
DATABASE
statement and specify the application container to drop.
Example 12-5 Dropping Application Container salesact While Keeping Its Data Files
DROP PLUGGABLE DATABASE salesact
KEEP DATAFILES;
Example 12-6 Dropping Application Container salesact and Its Data Files
DROP PLUGGABLE DATABASE saleact
INCLUDING DATAFILES;
See Also:
Creating and Removing Application Seeds
You can create application seeds in several different ways, including using the PDB seed, cloning an existing PDB or non-CDB, and plugging in an unplugged PDB. You can also remove application seeds from application containers.
Creating Application Seeds
You can use the CREATE PLUGGABLE DATABASE
statement to create an application seed in an application container.
About Creating an Application Seed
To create a new application seed in an application container, use the CREATE PLUGGABLE DATABASE
statement with the AS SEED
clause.
You can use an application seed to provision an application container with application PDBs that have the application root’s applications installed. Typically, the application container’s applications are installed in the application root before seed creation. After the application seed is created, it is synchronized with the application root so that the applications are installed in the application seed. When that is complete, any PDBs created using the application seed have the applications installed. When an application in the application root is upgraded or patched, the application seed must be synchronized with the application root to apply these changes.
An application container can have zero or one application seeds. When you create an application seed using the AS SEED
clause of CREATE PLUGGABLE DATABASE
, you do not specify its name. The application seed name is always application_container_name$SEED
, where application_container_name
is the name of the application seed’s application container. For example, an application seed in the salesact
application container must be named salesact$SEED
.
When you create a new application seed, you must specify an administrator for the application container in the CREATE PLUGGABLE DATABASE
statement. The statement creates the administrator as a local user in the application container and grants the PDB_DBA
role locally to the administrator.
See Also:
-
Oracle Database SQL Language Reference for syntax and semantics of the
AS SEED
clause
Preparing for an Application Seed
Prerequisites must be met before creating an application seed.
Ensure that the following prerequisites are met before creating an application seed:
-
The CDB must exist.
-
The CDB must be in read/write mode.
-
The application container to which the application seed will belong must be in read/write mode.
-
The current user must be a common user whose current container is the application root to which the application seed will belong.
-
The current user must have the
CREATE
PLUGGABLE
DATABASE
system privilege. -
For the application seed to include the application for the application container, the application must be installed in the application root.
Creating an Application Seed
You create an application seed by including the AS SEED
clause in the CREATE PLUGGABLE DATABASE
statement.
An application seed in an application container is similar to the seed in a CDB. An application seed enables you to create application PDBs that meet the requirements of an application container quickly and easily.
Example 12-7 Creating an Application Seed from the PDB seed
This example assumes the following factors:
-
The application seed is being created in an application container named
salesact
. -
Storage limits are not required for the application seed. Therefore, the
STORAGE
clause is not required. -
The application seed does not require a default tablespace.
-
The
PATH_PREFIX
clause is not required. -
The
FILE_NAME_CONVERT
clause and theCREATE_FILE_DEST
clause are not required.Either Oracle Managed Files is enabled for the CDB, or the
PDB_FILE_NAME_CONVERT
initialization parameter is set. The files associated with the PDB seed will be copied to a new location based on the Oracle Managed Files configuration or the initialization parameter setting. -
There is no file with the same name as the new temp file that will be created in the target location. Therefore, the
TEMPFILE REUSE
clause is not required. -
No predefined Oracle roles need to be granted to the
PDB_DBA
role.
The following statement creates the application seed from the PDB seed, opens the application seed, switches containers to the application seed, synchronizes the application seed with the applications in the application root, closes the application seed, and then opens the application seed in open read-only mode:
CREATE PLUGGABLE DATABASE AS SEED
ADMIN USER actseedadm IDENTIFIED BY password;
ALTER PLUGGABLE DATABASE salesact$SEED OPEN;
ALTER SESSION SET CONTAINER=salesact$SEED;
ALTER PLUGGABLE DATABASE APPLICATION ALL SYNC;
ALTER PLUGGABLE DATABASE CLOSE IMMEDIATE;
ALTER PLUGGABLE DATABASE OPEN READ ONLY;
Because the application container name is salesact
, the application seed name is salesact$SEED
.
A local user with the name of the specified local administrator is created and granted the PDB_DBA
common role locally in the application seed. If this user was not granted administrator privileges during application seed creation, then use the SYS
and SYSTEM
common users to administer to the application seed.
The application seed was synchronized with the application root when it was created. Therefore, the application seed includes the applications installed in the application root and the application common objects that are part of those applications. When a new application PDB is created using the application seed, the application PDB also includes the installed applications and application common objects.
Example 12-8 Creating an Application Seed From an Application PDB
This example assumes the following factors:
-
The application seed is being created in an application container named
salesact
. -
The application seed is being created in an application PDB in the application container named
salesapppdb
. -
Storage limits are not required for the application seed. Therefore, the
STORAGE
clause is not required. -
The application seed does not require a default tablespace.
-
The
PATH_PREFIX
clause is not required. -
The
FILE_NAME_CONVERT
clause and theCREATE_FILE_DEST
clause are not required.Either Oracle Managed Files is enabled for the CDB, or the
PDB_FILE_NAME_CONVERT
initialization parameter is set. The files associated with the application root will be copied to a new location based on the Oracle Managed Files configuration or the initialization parameter setting. -
There is no file with the same name as the new temp file that will be created in the target location. Therefore, the
TEMPFILE REUSE
clause is not required.
Given the preceding factors, the following statement creates the application seed from the application root, opens the application seed, closes the application seed, and opens the application seed in open read-only mode:
CREATE PLUGGABLE DATABASE AS SEED FROM salesapppdb;
ALTER PLUGGABLE DATABASE salesact$SEED OPEN;
ALTER PLUGGABLE DATABASE CLOSE IMMEDIATE;
ALTER PLUGGABLE DATABASE OPEN READ ONLY;
Because the application container name is salesact
, the application seed name is salesact$SEED
.
The application seed was created from an application PDB. Therefore, the application seed includes the applications installed in the application root and the application common objects that are part of those applications. When a new application PDB is created using the application seed, the application PDB also includes the installed applications and application common objects.
Example 12-9 Creating an Application Seed From an Application Root
This example assumes the following factors:
-
The application seed is being created in an application container named
salesact
. The application seed is cloned from the root of the application container. -
Storage limits are not required for the application seed. Therefore, the
STORAGE
clause is not required. -
The application seed does not require a default tablespace.
-
The
PATH_PREFIX
clause is not required. -
The
FILE_NAME_CONVERT
clause and theCREATE_FILE_DEST
clause are not required.Either Oracle Managed Files is enabled for the CDB, or the
PDB_FILE_NAME_CONVERT
initialization parameter is set. The files associated with the application root will be copied to a new location based on the Oracle Managed Files configuration or the initialization parameter setting. -
There is no file with the same name as the new temp file that will be created in the target location. Therefore, the
TEMPFILE REUSE
clause is not required.
Given the preceding factors, the following statement creates the application seed from the application root, opens the application seed, switches containers to the application seed, runs the pdb_to_apppdb.sql
script to convert the application root to an application PDB, closes the application seed, and opens the application seed in open read-only mode:
CREATE PLUGGABLE DATABASE AS SEED FROM salesact;
ALTER PLUGGABLE DATABASE salesact$SEED OPEN;
ALTER SESSION SET CONTAINER=salesact$SEED;
@$ORACLE_HOME/rdbms/admin/pdb_to_apppdb.sql
ALTER PLUGGABLE DATABASE CLOSE IMMEDIATE;
ALTER PLUGGABLE DATABASE OPEN READ ONLY;
Because the application container name is salesact
, the application seed name is salesact$SEED
.
The application seed was created from the application root. Therefore, the application seed includes the applications installed in the application root and the application common objects that are part of those applications. When a new application PDB is created using the application seed, the application PDB also includes the installed applications and application common objects.
Unplugging an Application Seed from an Application Container
You can unplug an application seed from an application container.
About Unplugging an Application Seed
Unplugging an application seed disassociates the application seed from an application container. You unplug an application seed when you no longer want the application seed to be available.
Unplugging an application seed is similar to unplugging a PDB. To unplug an application seed, connect to its application root and use the ALTER PLUGGABLE DATABASE
statement to specify an XML file or a .pdb
file. When you specify an XML file (.xml
extension), it will contain metadata about the application seed after it is unplugged. The SQL statement creates the XML file, and it contains the required information to enable a CREATE PLUGGABLE DATABASE
statement on a target CDB to plug it in as a PDB or an application PDB. When you specify a .pdb file, it contains a compressed archive of the XML file that describes the application seed and the files used by the application seed (such as the data files and wallet file). A .pdb
file enables you to copy a single, compressed file (instead of multiple files) to a new location to plug in as a PDB or an application PDB.
Before it can be unplugged, the application seed must be closed. When you unplug an application seed, the unplugged application seed is in mounted mode. The unplug operation makes some changes in the application seed’s data files to record, for example, that the application seed was successfully unplugged. Because it is still part of the application container, the unplugged application seed is included in an RMAN backup of the entire CDB. Such a backup provides a convenient way to archive the unplugged application seed in case it is needed in the future.
To completely remove the application seed from the application container, you can drop it. The only operation supported on an unplugged application seed is dropping the application seed. The application seed must be dropped from the application container before it can be plugged back into the same application container. An application seed is usable only when it is plugged into an application container.
See Also:
-
"Modifying the Open Mode of PDBs" for information about closing a PDB
-
"Modifying a PDB at the System Level" for information about initialization parameters and unplugged PDBs
-
Oracle Database Security Guide for information about common users and local users
Unplugging an Application Seed
To unplug an application seed, run the ALTER PLUGGABLE DATABASE ... UNPLUG INTO
statement.
Prerequisites
The following prerequisites must be met:
-
The current user must have
SYSDBA
orSYSOPER
administrative privilege, and the privilege must be either commonly granted or locally granted in the application container. The user must exercise the privilege usingAS SYSDBA
orAS SYSOPER
at connect time. -
The application seed must have been opened at least once.
Note:
If you are unplugging an application seed that includes data that was encrypted with Transparent Data Encryption, then follow the instructions in Oracle Database Advanced Security Guide.
To unplug an application seed:
-
In SQL*Plus, ensure that the current container is the application root of the application container to which the application seed belongs.
-
Close the application seed.
In an Oracle Real Application Clusters (Oracle RAC) environment, the application seed must be closed on all instances.
-
Run the
ALTER PLUGGABLE DATABASE
statement with theUNPLUG INTO
clause, and specify the application seed to unplug and the name and location of the application seed’s XML metadata file or .pdb file.
Example 12-10 Unplugging Application Seed salesact$SEED
This ALTER PLUGGABLE DATABASE
statement unplugs the application seed salesact$SEED
and creates the salesact$SEED.xml
metadata file in the /oracle/data/
directory:
ALTER PLUGGABLE DATABASE salesact$SEED
UNPLUG INTO '/oracle/data/saleact$SEED.xml';
Dropping an Application Seed
You can use the DROP
PLUGGABLE
DATABASE
statement to drop an application seed. You can drop an application seed when you no longer need it.
When you drop an application seed, the control file of the CDB is modified to eliminate all references to the dropped application seed. Archived redo log files and backups associated with the application seed are not removed, but you can use Oracle Recovery Manager (RMAN) to remove them.
When dropping an application seed, you can either keep or delete the application seed’s data files by using one of the following clauses:
-
KEEP DATAFILES
, the default, retains the data files.The application seed’s temp file is removed even when
KEEP DATAFILES
is specified because the temp file is no longer needed. -
INCLUDING DATAFILES
removes the data files from disk.If an application seed was created with the
SNAPSHOT COPY
clause, then you must specifyINCLUDING DATAFILES
when you drop the application seed.
The following prerequisites must be met:
-
The application seed must be in mounted mode, or it must be unplugged.
-
The current user must have
SYSDBA
orSYSOPER
administrative privilege, and the privilege must be either commonly granted or locally granted in the application container. The user must exercise the privilege usingAS SYSDBA
orAS SYSOPER
at connect time.
Note:
This operation is destructive.
To drop an application seed:
-
In SQL*Plus, ensure that the current container is the application root of the application container to which the application seed belongs.
-
Run the
DROP PLUGGABLE DATABASE
statement and specify the application seed.
Example 12-11 Dropping Application Seed salesact$SEED While Keeping Its Data Files
DROP PLUGGABLE DATABASE salesact$SEED
KEEP DATAFILES;
Example 12-12 Dropping Application Seed salesact$SEED and Its Data Files
DROP PLUGGABLE DATABASE saleact$SEED
INCLUDING DATAFILES;
Creating an Application PDB
You create an application PDB by running the CREATE PLUGGABLE DATABASE
statement with an application root as the current container.
You can create application PDBs using the same SQL statements that you use to create PDBs in the CDB root. The newly created PDB is an application PDB when the CREATE PLUGGABLE DATABASE
statement is run in an application root. The statement must be run in an application root and has an explicit dependency on the application database defined in that application root.